JPH04114025A - Polyurethane resin and imitation leather therefrom - Google Patents

Abstract

PURPOSE:To obtain the title resin improved in the resistance to deterioration due to oleic acid, useful for vehicle trim materials, synthetic imitation leathers, construction materials, vehicle coatings, wall trim material coatings etc., by using cyclohexane diisocyanate as polyisocyanate component. CONSTITUTION:The objective resin pref. 50000-200000 in molecular weight can be obtained by reaction between (A) a polyol (pref. polycarbonate polyol 1000-3000 in molecular weight), (B) cyclohexane diisocyanate, and (C) a chain extender (e.g. ethylene glycol).

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to polyurethane resin and simulated leather using the same, and more specifically to synthetic simulated leather that has excellent oleic acid resistance and is particularly suitable for vehicle interiors. Regarding.

(Prior art and its problems) Faux leather, which has a polyurethane resin layer on the surface of a base sheet made of woven fabric or non-woven fabric, has been widely used in various fields.Especially in recent years, with the increasing luxury of vehicles and In an effort to reduce weight, synthetic faux leather, which is lightweight and has a similar appearance to natural leather, is being widely used as an interior material in place of natural leather, which is in short supply.

These polyurethane fake leathers are required to have excellent weather resistance, discoloration resistance, and hydrolysis resistance, and to meet these requirements, polycarbonate polyols are used as polyols.
This problem has been dealt with by using aliphatic or alicyclic diisocyanates as polyisocyanates.

However, even if the above-mentioned polyurethane resin fake leather with improved durability is used for vehicle interior materials,
Particularly, there is a problem in that abnormal deterioration occurs in areas that come into contact with human skin.

According to the inventor's research, the above problem of abnormal deterioration is caused by oily substances contained in human sweat, especially oleic acid, repeatedly adhering to specific areas of the fake leather product and plasticizing the polyurethane resin. I compared things.

The present inventor has solved the drawbacks of the prior art as described above, and as a result of intensive research in order to meet the above demands, when forming a fake leather resin layer using a polyurethane resin made of a specific polyisocyanate, The present invention was completed based on the knowledge that the technical drawbacks were solved and that it was possible to provide fake leather that did not deteriorate even with human sweat.

(Means for Solving the Problems) That is, the present invention comprises a polyurethane resin characterized in that cyclohexane diisocyanate is used as a polyisocyanate component, and a resin layer provided on at least one surface of a base sheet, This is a fake leather characterized in that the resin layer is made of the above-mentioned polyurethane resin.

(Function) By forming the resin layer of the fake leather from a polyurethane resin using cyclohexane diisocyanate as a polyisocyanate component, a fake leather having excellent oleic acid resistance in addition to other excellent properties is provided.

(Preferred embodiment) Next, the present invention will be explained in more detail with reference to embodiments.

The polyurethane resin of the present invention is obtained by reacting a polyol, cyclohexane diincyanate, and a chain extender.

The polyol used in the present invention is a conventionally known polyurethane polyol, particularly a diol, and any conventionally known polyol can be used. For example, preferred ones include polyethylene adipate, polyethylene propylene adipate, and polyethylene propylene adipate having a molecular weight of 500 to 3.000. Polyethylene butylene adipate, polydiethylene adipate, polybutylene adipate, polyethylene succinate, polybutylene succinate, polyethylene sebacate, polybutylene sebacate, polytetramethylene ether glycol, poly-ε-caprolactone diol, polyhexamethylene adipate , polycarbonate polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, polyethylene polyol, polypropylene glycol, etc., and polyols containing an appropriate amount of polyoxyethylene chains in the above polyols.

Particularly preferred polyols in the present invention have a molecular weight of 1
,000 to 3,000 polycarbonate polyol.

Examples of chain extenders used in the present invention include:
Preferred are ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 16-hexanediol, 14-cyclohexane dimetatool m-xylylene glycol hydrogenated bisphenol A 1,4-bis(2-hydroxy Examples include ethoxy)benzene, bis(hydroxyethyl) terephthalate, 1,2-propylene diamine, trimethylene diamine, tetramethylene diamine, hexamethylene diamine, decamethylene diamine, isophorone diamine, m-xylylene diamine, hydrazine, and water.

The polyurethane resin of the present invention made of the above raw materials is
It can be easily obtained by conventionally known production methods, such as a batch reaction method of each component, a preborif method using a prepolymer, and the like. These polyurethane resins may be prepared without a solvent or in an organic solvent.

As for the reaction conditions, for example, a small amount of a reaction catalyst such as dibutyltin laurate, stannath octoate, or tertiary amine is used, and each component is mixed, for example,
A polyurethane resin having a desired molecular weight can be obtained by reacting at a temperature of about 0 to 200°C for several hours to more than ten hours.

The polyurethane resin preferably has a molecular weight of 30,000 to 300,000, and most preferably has a molecular weight of 50,000 to 200,000.

The resin layer of the fake leather of the present invention is preferably formed by dissolving or dispersing the above-mentioned polyurethane resin in a suitable solvent and using it in the form of a paint. Of course, the form of use is not limited to paint type. For example, in the case of a paint form, the concentration of the resin is preferably about 10 to 50% by weight.

The base sheet for the fake leather of the present invention may include various woven fabrics, non-woven fabrics, etc. that have been conventionally used as base sheets for fake leather, or these base sheets may be impregnated with resin or have a porous layer on their surface. In the present invention, a resin layer made of the above-described modifier and resin is formed on at least one surface of such a known base sheet.

The resin layer may be formed by any method (for example, a paint containing the polyurethane resin as an essential component is formed, applied or impregnated onto the surface of the base sheet, and dried to form the resin M. A method of forming a film by coating and drying these coatings on a release paper, and bonding the film to a base sheet, A method of forming a film from a resin by a calender method, etc. to form a resin layer. These resin layers may have any thickness, but for boat fishing, the thickness is about 0.1 to 100 μm.

In the present invention, any conventionally known additives such as colorants, plasticizers, antistatic agents, surfactants, anti-aging agents, crosslinking agents, etc. can be added to the resin layer. Of course.

(Example) Next, the present invention will be described in more detail by giving examples and comparative examples. Note that % in the text is based on weight unless otherwise specified.

Example A 1,6-hexane carbonate diol (molecular weight 200
0, hereinafter referred to as PC-2000) 200g and cyclohexadiisocyanate (hereinafter referred to as CHD■6) 32g
was charged into a 71130 flask, and reacted at 100'C for 4 hours with stirring.
A prepolymer was obtained. Pour 580g of dimethylformamide (DMF) into this, raise the internal temperature to 50'C, and add 16g of inphorondiamine (hereinafter referred to as PDA).
was added little by little to cause a molecular extension reaction, and the recovery level was 7 for 3 hours.
A viscous resin solution with a non-volatile content of 30% was obtained.

This solution was coated onto a polyester film using a coater adjusted to give a film thickness of around 60 μm.
i at 120”C for 20 minutes at ℃.

The film was dried in a dryer for a minute and left in a room at room temperature for 48 hours to form a film.The physical properties of the film were measured, and the results shown in Table 2 below were obtained.

Example B PC-2000200g, 1,6-hexanediol 2
3 g and CHDI 65 g were placed in a 2000 mρ 30 flask, and while stirring, the mixture was reacted at 100°C for 4 hours.
A prepolymer with NGO at both ends was obtained. DMF on this thing
250 g, isopropyl alcohol 250 g, and toluene 250 g, stirred until the contents became uniform, then added 32.5 g of IPDA little by little at an internal temperature of 50"C to perform a molecular extension reaction, and revived for 2.5 hours. degree 62
A viscous resin solution with 0 voids/20° C. and a non-volatile content of 29.9% was obtained.

A film was formed from this solution in the same manner as in Example A, and its physical properties were measured, and the results shown in Table 2 below were obtained.

Comparative Example C PC-2000 200g, 1,4-butanediol 13
g and 640 g of DMF were placed in 30 flasks and heated to 50°C.
The contents were stirred until the contents were homogeneous, and 61 g of MDI was charged and the reaction was carried out slowly at 60°C for 2 hours. In this way, a viscous resin reservoir with a viscosity of 480 boids/20°C and a non-volatile content of 29.9% was formed. I got the liquid.

A film was formed from this solution in the same manner as in Example A, and its physical properties were measured, and the results shown in Table 2 below were obtained.

Comparative Example D-J A polyurethane resin was synthesized using the materials shown in Table 1 below under the reaction conditions of Example A, and a film was similarly formed and its physical properties were measured, and the results shown in Table 2 below were obtained. It was done.

(Left below) The films formed in the above examples and comparative examples were immersed in oleic acid at 70°C for 24 hours, and the physical properties of the films before and after the test were measured, and the results are shown in Table 2 below. I got it.

1 ≦ U after 3.5 As is clear from Table 2 above, when compared with Comparative Example C, which uses an aromatic polyisocyanate and has no problem in oleic acid deterioration resistance (yellowing resistance is poor) , Examples A and B of the present invention are close to Comparative Example C in all retention rates and show good results, but the conventional non-yellow urethane resins of Comparative Examples D to J have 100% modulus retention and breaking strength retention. The ratio decreased extremely, and the elongation at break increased, indicating that the resin was plasticized by oleic acid.

Creation of synthetic simulated leather Synthetic simulated leather of the present invention and comparative example having the configuration shown in the first figure were created by following each step.

(1) First step 2 Preparation of colorant In order to check the color fastness of the resin, resins A and D synthesized above were prepared.
, 1 as a vehicle and the following formulations were dispersed in a ball mill for 24 hours to prepare white colorants A, D, and (2).

1 Two-in-one polyurethane resin A solution 30 parts Titanium oxide 50 parts Solvent (IPA/Toluene = 1/1) 20 parts 1 Color counting polyurethane resin solution 30 parts Titanium oxide 50 parts Solvent (IPA/Toluene = 1/1) 20 parts One-color polyurethane resin I solution 30 parts Titanium oxide 50 parts Solvent (IPA/Toluene = 1/1) 20 parts (2) Second step: Preparation of paint compound and base film layer Each with the following formulations It was prepared by blending the corresponding polyurethane resin and colorant.

Polyurethane resin 100 parts Colorant
20 parts mixed solvent (IPA
/toluene/DMF=1/1/1)
40 parts of the above coating material was applied onto a release paper to give a film thickness of 25 μm, and dried in a dryer at 100° C. for 2 minutes to form a base film layer.

(3) Third step: Preparation of adhesive An adhesive was prepared with the following formulation.

Polyurethane resin A solution 100 parts Mixed agent (IPA/h toluene/DMF=1/1/2)
40 parts The above adhesive was applied on the film prepared in the second step at a rate of 80 g/bo (wet), dried at 70°C for 1 minute, laminated with a nonwoven fabric using a laminating machine, and then heated at 100°C for 2 minutes. Dry for a minute.

(4) Fourth step: Creation of fake leather Dilute the polyurethane resins B, H and J with a mixed solvent of IPA/toluene = 1/1 to 150 cps/2.
The temperature was adjusted to 5°C and used as a surface treatment agent. Peel off the release paper of the synthetic fake leather created in the third step, apply 100 mesh once with a gravure coater, dry at 100℃ for 30 seconds, and put on a coating film of about 3μm, making it more similar to natural leather. Finished with a surface look.

Twelve types of synthetic fake leather were created by combining each material using the above method. Their composition is shown in Table 3 below.

The results of various durability tests conducted on the above 12 types of fake leather are shown in Table 4 below.

Weather resistance deterioration test: Using a sunshine fade meter, the black panel was irradiated for 400 hours at a temperature of 83° C., and a value of △E2 or less was evaluated as a pass (◯) using a color difference meter. Flexibility was evaluated as passing (◯) when measured 20,000 times or more at room temperature using a flexometer.

Hydrolytic deterioration test: Jungle test at 70℃, 9
It was treated for 10 weeks at 5% RH, and was passed (○) with no stickiness on the surface and an adhesive strength retention rate of 70% or more.

Heat resistance deterioration test: Tested in a gear oven at 120℃ for 400 hours, and passed if the discoloration by color difference meter was △E2 or less (0
).

Oleic Acid Deterioration Resistance Test The samples were immersed in oleic acid at 70°C for 24 hours, and the surface abrasion properties were examined using a taper abrasion tester using a C5-10 wear ring, a load of Ikg, and 2000 cycles to check for abnormalities that occur on the surface.

○: No abnormality △: Slight abnormality ×: Large abnormality (effect) As described above, the polyurethane resins conventionally used as highly durable polyurethane resins have sufficient properties except for oleic acid deterioration resistance. It has durability. However, it is plasticized by oily substances contained in human sweat, especially oleic acid, and when used in synthetic fake leather, the abrasion strength is extremely reduced and unexpected breakage occurs during long-term use.

On the other hand, the fake leather of the present invention has significantly improved resistance to oleic acid deterioration, and for example, when used as a vehicle interior material,
In particular, it can exhibit sufficient durability even when used for steering wheel covers and seat parts that come into direct contact with people's hands and waists. Of course, the fake leather of the present invention has many uses other than vehicle interior materials.

Further, the polyurethane resin of the present invention utilizes the various excellent durability explained above, and can be used in addition to synthetic fake leather.
For example, it is useful as a binder for building materials, vehicle paints, wall covering paints, and magnetic materials.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating a cross section of the fake leather produced according to the present invention.

Claims (3)

[Claims] (1) A polyurethane resin characterized by using cyclohexane diisocyanate as a polyisocyanate component. (2) A fake leather comprising a resin layer provided on at least one surface of a base sheet, the resin layer comprising a polyurethane resin using cyclohexane diisocyanate as a polyisocyanate component. (3) The imitation leather according to claim 1, which is used for vehicle interiors.